The Octopus Orphnoch is an Orphnoch who assumed the form of a young man and an antagonist in Kamen Rider 555.
Kamen Rider 555
He fought Faiz and was destroyed by Faiz's Crimson Smash.
Kamen Rider Decade
The Octopus Orphnoch appeared as part of a group of Orphnochs that attacked Natsumi and Tsukasa Kadoya during the shifting of the worlds. He and his comrades were defeated by Tsukasa using Kamen Ride: Faiz.
OOO, Den-O, All Riders: Let's Go Kamen Riders
In the alternate future where Shocker achieved their goal of world dominion with their kaijin Shocker Greeed, the Octopus Orphnoch was one of the Orphnochs that joined Shocker. He later participated in the final battle between the Kamen Riders and Shocker and was defeated alongside Lobster Orphnoch, Elephant Orphnoch and Stag Beetle Orphnoch by Faiz.